Effect of different doses of IFN--#gamma# on the development of mouse H22 hepatoma

Sustained low-level expressed of IFN-#gamma# significantly promoted H22 tumor development after injection of mIFNG plasmid with dosage 10#mu#g×8. Sustained expression of IFN-#gamma# blockade could inhibit the tumor-promoting effect of IFN-#gamma#. However, transitory expression of IFN-#gamma# did not have such effect when mice were injected twice with 10#mu#g of mIFNG plasmid. On the other hand, sustained high-level expression of IFN-#gamma# mediates significant antitumor effect when mice received 100#mu#g of mIFNG plasmid injections for 8 times. Our results suggest that IFN-#gamma# functions as a double-edged sword in mouse H22 tumor development and may function as an important shifting mechanism from chronic inflammation to tumor development.